//最长递增子序列的个数
//测试链接：https://leetcode.cn/problems/number-of-longest-increasing-subsequence/
public class FindNumberOfLIS {
    public int findNumberOfLIS(int[] nums) {
        int n = nums.length;
        int[] len = new int[n];
        int[] count = new int[n];
        for (int i = 0; i < n; i++)
            len[i] = count[i] = 1;
        int retlen = 1, retcount = 1;
        for (int i = 1; i < n; i++) {
            for (int j = 0; j < i; j++) {
                if (nums[j] < nums[i]) {
                    if (len[j] + 1 == len[i]) // 计数
                        count[i] += count[j];
                    else if (len[j] + 1 > len[i]) // 重新计数
                    {
                        len[i] = len[j] + 1;
                        count[i] = count[j];
                    }
                }
            }
            if (retlen == len[i])
                retcount += count[i];
            else if (retlen < len[i]) // 重新计数
            {
                retlen = len[i];
                retcount = count[i];
            }
        }
        return retcount;
    }
}
